How the calculation works
The calculator follows these steps from the IRS form or worksheet, in order.
- Standard side: the base amount for the year and filing status, plus the add-on for each age 65+ or blindness box.
- Add-on per box: $1,600 for 2025 and $1,650 for 2026; $2,000 and $2,050 if unmarried and not a surviving spouse.
- 2026 only: add cash gifts to charity up to $1,000 ($2,000 joint), which non-itemizers can deduct.
- Itemized side: SALT after the limit, mortgage interest, charitable gifts, medical costs above 7.5% of AGI, and other itemized amounts.
- For 2026 above the SALT threshold, itemized deductions are shown as a range between the floor and the cap.
Source: IR-2025-103, 2026 inflation adjustments; Rev. Proc. 2025-32. Checked on IRS.gov October 21, 2026.